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ANDRZEJ JEZIORSKI/MUNICH
AIRCRAFT EMISSIONS are just one, probably a relatively minor, contributor to anthropogenic environmental change. Yet, combined with all the other natural
and man-made contributors, the prognosis for
climatic change over the next half century is
both worrying and insufficiently researched.
To date, nobody has had a research platform
which can probe high enough, linger long
enough and travel far enough at high altitude,
to give a reliable picture of what is really hap
pening to the upper atmosphere. Until such
data have been gathered, nobody can tell just
how much work and investment is needed to
ensure that any polluting industry, including air
transport, can keep developing in an ecological
ly acceptable way. Neither can anyone tell for
sure whether efforts being made now are suffi
cient, inadequate or, perhaps, excessive.
It seems strange, then, that a high-altitude
research aircraft which could provide die sort of
firm evidence needed should now be threatened
by apparent Government apathy in a country
where both "green" issues and aerospace are
high on the political agenda. Yet that is what is
happening to the Grob Strato 2C.
The aircraft, built by German manufacturer
Burkhart Grob Luft- und Raumfahrt, is intend
ed to be operated with two pilots, two scientists
and experimental equipment, at up to 72,100ft
(22,000m) for up to 5h. Composites specialist
Grob says that its creation could be flown non
stop nearly half-way around the world.
At a distance, the Strato — which has an
empty weight of 7,600kg and a maximum take
off weight of 13,500kg — could almost be mis
taken for one of the sleek gliders with which
Grob first made its name, but the impression is
belied by its two large engines with pusher
props mounted atop the wing.
Up close, the Strato's proportions are star-
ding. On its own, die fuselage looks like that of
a 30-seat regional turboprop. The high-aspect
ratio, high-mounted wing gives the aircraft its
sailplane silhouette, but with nearly die span of
a Boeing 747. At 56.5m, this is the largest all-
composite wing ever made. The variable-pitch
propellers from MT-Propeller are great, five-
bladed windmills, 6m across, driven by a com
pound-propulsion system developed by
Ottobrunn-based scientific and technical ser
vices firm IABG, while the empennage is a tall
T-tail, rising 7.8m above the ground when the
aircraft is parked — as indeed the Strato has
remained for some time now, because of the
current wrangle over outstanding funds.
MONEY TROUBLES
The programme's funding has been divided
between the state — specifically die education,
science, research and technology ministry —
and the manufacturer. Development costs were
first estimated at DM93.4 million ($63 million),
of which the Government was to cover DM72
million, and die manufacturer the rest. This has
been enough to complete the first phase of
development, but the delay in the next tranche
of funding has cost Grob millions more. The
delay may now turn out to be permanent.
The programme started in April 1992, fol
lowing a recommendation from the ministry
and researchers to intensify stratospheric re
search in Germany. The German Aerospace
Research Establishment (DLR) was commis
sioned to manage the project, and was to have
been die end user.
The schedule anticipated a development pro
gramme lasting from 1992 to 1995, in parallel
with the establishment of a ground-support
infrastructure by the DLR at its Ober-
pfaffenhofen site in Bavaria. The preparation of
the first missions was planned for the beginning
of 1996, and the aircraft was scheduled to be
operational from 1996 to 2000. One of die main
areas targeted for research (among various cli
matic, chemical and technical investigations)
was pollution caused by air traffic, and its influ
ence on trace gases and die radiation field.
Grob was selected as the manufacturer be
cause of its expertise in composite-aircraft con
struction: metals could not provide the strength
and surface finish necessary for flight in thin air
at extreme altitudes. The company also had
experience in the high-altitude aircraft field
from the Egrett programme — a joint venture
with E-Systems of the USA to meet the
German air force LAPAS 1 observation aircraft
66 FLIGHT INTERNATIONAL 31 January - 6 February 1996